From a9b873c00599fbcfa38cbaf058f9846732a4f773 Mon Sep 17 00:00:00 2001 From: hackbard Date: Thu, 22 Oct 2009 19:54:17 +0200 Subject: [PATCH] more intesrtitial confs of c in si --- posic/talks/upb-ua-xc.tex | 67 +++++++++++++++++++++++++-------------- 1 file changed, 43 insertions(+), 24 deletions(-) diff --git a/posic/talks/upb-ua-xc.tex b/posic/talks/upb-ua-xc.tex index f1f60f4..78b1ef5 100644 --- a/posic/talks/upb-ua-xc.tex +++ b/posic/talks/upb-ua-xc.tex @@ -1969,6 +1969,7 @@ $z,x'$-axis rotation: $45.0^{\circ}$, $0.0^{\circ}$ } \includegraphics[width=6cm]{c_00-1_0-10_mig_vasp.ps} + \includegraphics[width=6cm]{c_00-1_0-10_mig_dis_vasp.ps} \end{slide} @@ -2103,6 +2104,32 @@ $z,x'$-axis rotation: $45.0^{\circ}$, $0.0^{\circ}$ \end{slide} +\begin{slide} + + {\large\bf\boldmath + Carbon point defects in silicon + } + + \begin{minipage}{3.2cm} + \underline{C tetrahedral}\\ + Relaxes into \hkl<0 0 1> configuration\\[0.2cm] + \underline{C hexagonal}\\ + Relaxes into \hkl<0 0 1> configuration\\[0.4cm] + \underline{\hkl<1 1 0> interstitial} + \begin{itemize} + \item $E_{\text{f}}=3.60\text{ eV}$ + \end{itemize} + \includegraphics[width=3cm]{c_pd_vasp/110_2333.eps} + \end{minipage} + \begin{minipage}{9cm} + \begin{center} + \includegraphics[height=8cm]{c_pd_vasp/110_2333_ksl.ps} + {\scriptsize \hkl<1 1 0> interstitial} + \end{center} + \end{minipage} + +\end{slide} + \begin{slide} {\large\bf\boldmath @@ -2112,12 +2139,13 @@ $z,x'$-axis rotation: $45.0^{\circ}$, $0.0^{\circ}$ \begin{itemize} \item Supercell: $3\times 3\times 3$ Type 2 \item Starting configuration: \hkl<0 0 -1> C-Si interstitial + ($E_{\text{f}}=3.15\text{ eV}$) \item Energies: $E_{\text{f}}$ of the interstitial combinations in eV \end{itemize} \underline{Along \hkl<1 1 0>:} - \begin{tabular}{|l|p{1.8cm}|p{1.8cm}|p{1.8cm}|p{1.8cm}|} + \begin{tabular}{|l|p{2.0cm}|p{1.8cm}|p{1.8cm}|p{1.8cm}|} \hline {\scriptsize \backslashbox{2nd interstitial}{Distance $[\frac{a}{4}]$} @@ -2141,7 +2169,7 @@ $z,x'$-axis rotation: $45.0^{\circ}$, $0.0^{\circ}$ \hline \hkl<-1 0 0>, \hkl<0 -1 0> & 3.92 & 4.43 & 6.02 & 6.02 \\ \hline - Vacancy & ... & ... & ... & ... \\ + Vacancy & 1.39 ($\rightarrow\text{ C}_{\text{S}}$)& 5.81 & 5.47 & 6.50 \\ \hline \end{tabular} @@ -2208,19 +2236,19 @@ $z,x'$-axis rotation: $45.0^{\circ}$, $0.0^{\circ}$ \hline & 2 & 3 & 4 & 5 & 6 \\ \hline -\hkl<0 0 -1> & 6.23 & 5.16 & 6.23 & ... & 4.65\\ +\hkl<0 0 -1> & 6.23 & 5.16 & 6.23 & 6.35 & 4.65\\ \hline -\hkl<0 0 1> & 6.64 & 6.31 & ... & ... & 4.78 \\ +\hkl<0 0 1> & 6.64 & 6.31 & 4.26 & 6.57 & 4.78 \\ \hline -\hkl<1 0 0> & 4.06 & 6.13 & 6.21 & ... & 4.93 \\ +\hkl<1 0 0> & 4.06 & 6.13 & 6.21 & 6.03 & 4.93 \\ \hline -\hkl<-1 0 0> & \hkl<0 -1 0> & 4.41 & ... & ... & 4.43 \\ +\hkl<-1 0 0> & \hkl<0 -1 0> & 4.41 & 4.06 & 6.19 & 4.43 \\ \hline \hkl<0 1 0> & \hkl<1 0 0> & 5.95 & \hkl<-1 0 0> & \hkl<-1 0 0> & \hkl<1 0 0> \\ \hline -\hkl<0 -1 0> & 3.92 & ... & \hkl<1 0 0> & \hkl<1 0 0> & \hkl <-1 0 0> \\ +\hkl<0 -1 0> & 3.92 & 4.15 & \hkl<1 0 0> & \hkl<1 0 0> & \hkl <-1 0 0> \\ \hline -Vacancy & ... & ... & ... & ... & ... \\ +Vacancy & 1.39 & 6.19 & 3.65 & 6.24 & 6.50 \\ \hline \end{tabular} @@ -2273,11 +2301,11 @@ Vacancy & ... & ... & ... & ... & ... \\ Reminder (just for me to keep in mind ...) } - \scriptsize + \small \underline{Volume of the MD cell} \begin{itemize} - \item $T=900\text{ K}$ + \item $T=450, 900, 1400\text{ K}$ - (no melting, N\underline{V}T!) \item $\alpha=2.0 \cdot 10^{-6}\text{ K}^{-1}$ \item $a = a_0(1+\alpha \Delta T)$ \item Plain Si$(T=0)$: $a_0=5.4575\text{ \AA}$ @@ -2286,27 +2314,18 @@ Vacancy & ... & ... & ... & ... & ... \\ \frac{1}{3}(a_0^x+a_0^y+a_0^z)=5.4605\text{ \AA}$ $\rightarrow a(900\text{ K})=5.4704{ \AA}$ \end{itemize} - Used in the 900 K simulations: 5.4705 \AA\\ - Consider next thoughts as well! + Used in first 900 K simulations: 5.4705 \AA\\ + BUT: Better use plain Si lattice constant! (only local distortions)\\ + $\Rightarrow a(1400\text{ K})=5.4728\text{ \AA}$ \underline{Zero total momentum simulations} \begin{itemize} \item If C is randomly inserted there is a net total momentum \item No correction in the temperature control routine of VASP? - \item Relax a Si:C configuration first (at T=0) + \item Relax a Si:C configuration first + (at T=0, no volume relaxation, scaled volume) \item Use this configuration as the MD initial configuration \end{itemize} - Two possibilities regarding volume which came to my mind: - \begin{enumerate} - \item Calculate and use an averaged $a_0$ (in each direction) - from the relaxed configuration. - Else there might be a preferred orientation for the defect. - \item On the other hand this might be important - for the way defects agglomerate. - Continue using the relaxation results. - \end{enumerate} - In both methods the corrections due to the non zero temperature - are applied! \end{slide} -- 2.20.1